Neonatal hypothyroidism

Definition

Neonatal hypothyroidism is decreased thyroid hormone production in a newborn. In very rare cases, no thyroid hormone is produced.

If the baby was born with the condition, it is called congenital hypothyroidism. If it develops soon after birth, it is called hypothyroidism acquired in the newborn period.

Causes

Hypothyroidism in the newborn may be caused by:

A thyroid gland that is not fully developed is the most common defect. Girls are affected twice as often as boys.

Symptoms

Most affected infants have few or no symptoms. This is because their thyroid hormone level is only slightly low. Infants with severe hypothyroidism often have a unique appearance, including:

This appearance usually develops as the disease gets worse.

The child may also have:

Exams and Tests

A physical exam may show:

Blood tests are done to check thyroid function. Other tests may include:

Treatment

Early diagnosis is very important. Most of the effects of hypothyroidism are easy to reverse.

Thyroxine is usually given to treat hypothyroidism. Once the child starts taking this medicine, blood tests are regularly done to make sure thyroid hormone levels are in a normal range.

Outlook (Prognosis)

Getting diagnosed early usually leads to a good outcome. Newborns who are diagnosed and treated in the first month or so usually have normal intelligence.

Untreated mild hypothyroidism can lead to severe intellectual disability and growth problems. The nervous system goes through important development during the first few months after birth. Lack of thyroid hormones can cause damage that cannot be reversed.

Possible Complications

When to Contact a Medical Professional

Call your health care provider if:

Prevention

If a pregnant women takes radioactive iodine for thyroid cancer, the thyroid gland may be destroyed in the developing fetus. Infants whose mothers have taken such medicines should be observed carefully after birth for signs of hypothyroidism.

Most states require a routine screening test to check all newborns for hypothyroidism.


Review Date: 6/16/2013
Reviewed By: Shehzad Topiwala, MD, Consultant Endocrinologist, Vera Endocrine Associates, Daytona Beach, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

This information should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. © 1997- 2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.